* Graphic: World FX rates in 2020 tmsnrt.rs/2egbfVh * Graphic: Trade-weighted sterling since Brexit vote tmsnrt.rs/2hwV9Hv LONDON, March 2 (Reuters) - Sterling eased to its lowest level against the dollar in two and a half weeks on Tuesday, as the strengthening U.S. currency put a brake on gains that had taken the pound to 2-1/2-year highs last week. The pound has so far been the best performing G10 currency in 2021, up 1.65% against the dollar, although its lead over other currencies is diminishing. Bets that Britain’s rapid vaccine rollout would underpin an economic rebound boosted sterling as far as 4.2% above its year-end price to the dollar as recently as last week. However, expectations of a faster U.S. economic recovery and for the Federal Reserve to show greater tolerance to higher bond yields than other central banks have boosted the greenback in recent days. By 0838 GMT, sterling was 0.2% lower at $1.3897, earlier hitting a 2-1/2 week low of $1.3867. It was flat to the euro at 86.42 pence. “Momentum in sterling has somewhat eased in the past few days, but ever more encouraging data on vaccination and contagion in the UK should continue to underpin hopes of a faster recovery, and keep a floor under the currency,” ING said in a note to clients. British house price growth picked up unexpectedly last month, mortgage lender Nationwide said on Tuesday, defying expectations of a slowdown as finance minister Rishi Sunak prepares new budget measures to boost the market. House prices rose 6.9% in annual terms in February from 6.4% in January, Nationwide said, above all forecasts in a Reuters poll of economists that had pointed to a slowdown to 5.6%.